1. Field of the Invention
The present invention relates to a caliper piston construction and more particularly to a piston construction which allows for increased heat isolation.
2. Description of Related Art
Many vehicles today simultaneously employ two types of braking systems: disc and drum. It is widely accepted, however, that disc brakes provide the majority of the stopping power. Thus, conventional braking systems can be improved by converting existing drum brakes to disc. Disc brakes can be further improved by switching to calipers which employ multiple pistons.
An example of a disc brake employing multiple pistons is U.S. Pat. No. 5,284,227 to Pelfrey. Furthermore, U.S. Pat. No. 4,505,363 to Herbulot et al. discloses a twin-disc brake system employing multiple pistons. Lastly, U.S. Pat. No. 4,064,974 to Filderman discloses an actuator mounting system for a multiple piston system.
While each of these braking systems achieves its own particular objective, none of them provides a construction with improved heat isolating characteristics. Furthermore, none of the above referenced systems limits the amount of air which escapes into the brake fluid lines.
Therefore, it can be appreciated that there exists a continuing need for a new and improved brake system which can be used for heat isolation and air intake reduction. In this regard, the present invention substantially fulfills this need.
The general purpose of the present invention is to provide an improved piston construction for use within a brake caliper.
To attain this, the present invention essentially comprises an improved disc braking system of the type employing two mating housings. Each housing has a pair of cylindrical piston receiving recesses. Each of the piston receiving recesses is adapted to support a base mounted spring. A brake fluid inlet passage and an upstanding seal are formed adjacent an opened end of the piston recess. The brake system is further adapted to support a slidably positioned brake pad formed adjacent the opened ends of the piston recesses. An improved piston structure is provided. The piston structure is fabricated of a metallic material. Next provided as part of the piston structure is a cylindrical base portion formed from a major diameter. The base portion has an annular spring receiving recess formed therein with a base mounted coil spring received within the annular recess. A cylindrical recess formed within the length of the base portion is provided. An elastomeric o-ring is provided. The o-ring is positioned within the recess and has an outer surface adapted to form a fluid-tight seal with a cylindrical piston recess of the brake system. Next provided is a cylindrical brake pad engaging portion formed from a minor diameter. A thin layer of metallic material is integrally formed in the remainder of the piston and is adapted to engage the surface of an adjacent brake pad. A cylindrical recess is formed within the length of the engaging portion and is adapted to receive a peripheral edge of the upstanding seal of the braking system. Lastly, a threaded aperture extends through the thin layer of metallic material and into the adjacent portion of the piston. In this manner, the thin layer of metallic material may be removed and replaced by a heat isolating material and retained by a bolt.
It is therefore an object of the present invention to provide an improved piston construction for use within a brake caliper.
It is another object of the present invention to provide a piston construction which efficiently isolates the heat generated during braking operations.
It is a further object of the present invention to provide an improved piston construction which limits the amount of air which escapes into the brake lines.
An even further object of the present invention is to provide a brake system which reduces maintenance needs.
Even still another object of the present invention is to provide a piston construction which is light weight and easy to manufacture.
Lastly, it is an object of the present invention to provide an improved piston structure for use in a brake caliper having a cylindrical base portion having an annular receiving recess and a base mounted spring received therein. A cylindrical brake pad engaging portion has an annular recess formed within its length. A recess is formed within the length of the base portion with an elastomeric o-ring positioned within the recess. A thin layer of metallic material is integrally formed with the remainder of the piston. The thin layer of metallic material is adapted to engage the surface of an adjacent brake pad.